The present apparatus is test apparatus for use in testing heat exchanger pipes. A heat exchanger is formed of a multitude of U-shaped, long, thin pipes with cooling fins on the exterior. The cooling fins transfer heat from the liquid flowing in the U-shaped tubing to the exterior. The tubing, itself, therefore, must be leak-proof. This tubing is normally formed in a U-shape and has a set of fins affixed to its exterior. It is fabricated in shops which build hundreds of sets of such tubing, a quantity which may be found only in heat exchangers. The tubing is normally placed inside a chamber or cavity for exposure to a coolant, and the U-shaped heat exchanger tubes extend to the exterior where they typically connect with some kind of inlet header and an outlet header. The present invention reduces the time required to apply one hundred percent quality control testing to all the tubes. The present invention is able to quickly connect and disconnect to a given U-shaped tubing member. It enables the member to be tested by applying water under pressure to a test level. Assume, for instance, that the test level is 2,000 psi. Assume further that the test pressure must be held for five minutes. Assume further that the tubing must be visually inspected for leaks along the length of the tubing. With a test criteria of this sort, the present invention is able to quickly connect and subsequently disconnect to a given tubing. It is hydraulically actuated, using the pressure of the water, itself. This is a distinct advantage, and it is particularly advantageous because there is no need to thread the ends, dope threaded connections, carefully align threaded fittings or undertake other steps of this sort. Rather, the end of the tubing to be tested is simply stabbed into the fitting of the present invention and held there until water pressure is increased. As the pressure increases, the equipment is set in response to the change in pressure. The test is then completed by making the necessary observations at the desired static pressure level.
With the background of the situation described above, the present invention thus defines a quick disconnect fitting which is adapted to pressure test heat exchanger tubing, the test apparatus comprising a quick disconnect fitting for high pressure testing. It includes an outer body which is counterbored. The outer body contains a set of collets which are acted on by thrust rings which respond to water under pressure introduced at the end of the test fitting. Water under pressure forces a ring against the collet fingers, and the collet fingers jam, thereby wedging against the surrounding support for them and locking the pipe. The locking force which holds the pipe in the test fixture exceeds the axial thrust created by the water which would otherwise expel the pipe.